Zuko's Promise
by PoeticMoonSpirit
Summary: Zuko made Katara a promise—a promise he intends to keep. A fic for our very first Zutara Exchange!
1. The Agni Kai

_**Chapter 1: The Agni Kai**_

Destiny is never what you expect. It can take you places you never thought possible. And sometimes places you never even wanted. The first few years of his banishment, Zuko thought his destiny was to capture the avatar. But somewhere deep inside him, he always felt it was wrong. But he also squashed those feelings of doubt, in favor of going home and impressing his father. But ever since joining the Avatar and his friends, he knew he finally found his destiny. And now he was taking his destiny to face Azula… something he wished he would never have to do.

It wasn't that Zuko was scared of Azula. He knew he could take her. He felt it in his bones. He was scared of the possibility of losing a part of himself. The part that secretly sought his sister's former affection for him—the part, no matter how irrational, that just wanted her approval.

He also knew that if he needed help, Katara would back him up in any way possible.

He just knew.

So many things had changed in the last few months. He left the Fire Nation to join the Avatar's forces to put a stop to his father's forces for good. He became best friends with Katara—his former enemy. Who knew they'd work so well together? After the war, he thought they could spar again for old times' sake. He missed the adrenaline rush he felt when fighting her. _Perhaps it was a Katara thing,_ he inwardly chuckled, but when he fought her, it almost felt like fighting himself. They were so equally matched in every way that it always felt right to have her by his side.

But today was not a day to reminisce on happy memories—old or new. Right now he was facing his sister. His sister who was always sick, but today, seemed to have become officially _broken_. To say he was shocked would be an understatement. Her eyes held a vulnerability he never saw. He saw weakness. But he also saw uncertainty. And Azula is most dangerous when she was unpredictable. Zuko always knew what to expect with Azula. The unexpected. But not on this scale. This wasn't good, and unless he ended this quick, he didn't know if he would be able to live to see another day. He had to finish this.

If only he hadn't been so reckless. If only he hadn't let his guard down…

"No lightning today? What's the matter? Afraid I'll redirect it?"

A menacing scowl appeared on his sister's face. "Oh, I'll show you _lightning_!"

He should've known. He should've seen it coming from a mile away.

Azula was not one to miscalculate. Even in her deranged state, he could see her formulating a plan in the midst of their duel. He was so focused on preparing to redirect lightning. He didn't even realize Katara had entered the arena.

Oh, if only he knew.

But he didn't know and wasn't fast enough. He wasn't.

* * *

_"Zuko, would you quit it? I'm trying to bend here!" Katara shouted, exasperated._

_"Well, I'm sorry that I'm the only one worried about the comet tomorrow!"_

_Silence._

_"Zuko...why do you think I'm bending right now? I'm trying to calm myself too. But you keep pacing around me and it's a bit unnerving!"_

_He bit his lip and looked down. "Sorry."_

_Katara sighed and pulled her arms in, releasing the water. "It's okay. It's alright to be scared, you know? We may not come out of it alive."_

_"Don't say that."_

_"But it's true and you know it. Your sister is crazy and I'm sure she wouldn't have a problem ending either of us." She shrugged._

_Zuko sighed. "Point taken. But we're prepared. We can handle her."_

_She paused for a moment. "I wanna ask you something."_

_He didn't even blink. "What is it?"_

_"Just hear me out. I know you won't like where I'm going with this, but I want you to listen." Zuko tensed._

_"If I die tomorrow," Zuko's hands clenched, "I want to you to promise me something. Promise me you'll assist the Water Tribes in any way possible. I won't...I won't be there to help, so I'd like it if you could provide some kind of assistance. At least for the first year after the war."_

_His heart clenched at the very thought of Katara no longer being in his life anymore. This girl changed him for the better. He'd be lying if he said she was't the reason he changed sides. His Uncle may have been the one to convince him over time. But Katara was the one who saw him at his worst and still decided to trust him. She was the first one, who wasn't blinded from familial rose colored glasses, to really believe he could change. To trust him. Even when he couldn't trust himself. The fact that she even had to ask-_

_ "You don't even have to ask. You know I will."_

_She gave him a sad smile. "Also, I want my body to be cremated," She swallowed, "I want you to be the one to throw my ashes into the sea near the Southern Water Tribe. I want my people to know that I'll always be watching over them."_

_"I-" Why was she doing this? Doesn't she know he can't live without her? Doesn't she know that if anyone was going to die, it would be him? He would never let anything happen to her. But telling her would only put her in danger. He knew if he told her, she would be even more likely to put herself in danger for his sake. She was a lot like him in a lot of ways. It's one of the things he loved about her…__She looked up into his eyes. Tears he didn't even know he was shedding were falling into her hands. _

_"I'm sorry. I know this is hard. But this is just worst case scenario stuff. I don't want to have any regrets."__The only regret he'd have was not being able to tell her how he felt. But he couldn't tell her now. War was no time for love. So he said something else and hoped she got the message. "Katara, you have no idea how hard this is. You're the first real friend I've ever had. Almost everyone I've ever loved either turned on me or left me. I can't," He shook his head, "I can't lose you too. I just can't."_

_She threw her arms around him as his cries turned into sobs. In all his life he never cried so loudly. He learned to master the ability to cry in silence. Having Ozai as a father, where crying was known as weakness and weakness meant punishment, didn't give him much of a choice. But holding her in his arms—possibly for the last time...not even the toughest training of silence could stop him from crying the way he was now. The scent of firewood and fire lilies filled her nose as she cried with him. She wasn't sure if she'd ever get to hug him again, but she squeezed him tight regardless._

_"I love you." Screw propriety. Screw timing. If he didn't tell her now. He might never get the chance. _

_She gasped as she broke away from him.__"What...what did you say?"_

_Might as well say it as many times as possible before the possible end."I said I love you. I need you to know… Whatever happens, I'll always love you."_

_She looked him in the eyes, smiling with crinkled eyes. "I love you too, Zuko." __That settled it. There was no way he would let anything ever harm this girl._

* * *

Azula held her finger tips in, as the scorching blue lightning formed on them. A sinister smile appeared on her face as she released it.

Zuko didn't even hesitate to move. He couldn't.

The lightning was aiming straight towards him, but a flash of soft blue made its way in front of him before he could protest.

_"NO!"_

The light from the bolt seized Katara's body as she twitched from the excruciating pain. With a small cry, she fell into a small heap in the middle of the arena.

Zuko ran so fast that he didn't even remember breathing. He flipped Katara over and gasped.

Scorch marks covered most of her chest and face, while most of her sarashi was burned, shreds of the remaining cloth covered her burnt skin. The lightning most likely pierced right through her stomach. Tears welled up in his eyes, from despair or anger? Zuko didn't know. He began shaking her, hoping he would get a reaction from her still body.

"Katara. Katara, please...please say something! _Anything_!"

She slowly opened her eyes and tried to sit up, but only resorted to coughing up dark clumps of blood.

She weakly grasped at her necklace in an attempt to unclasp the pendant.

"Zuko, here...Take it. I want you to have it."

"W-What? No. No way! You can heal yourself, can't you? You'll make it, we just need—"

She gave him a sad smile. "Zuko, we both know I won't. I'm not going to make it. I...I won't."

Zuko clenched his jaw and closed his eyes as his hands trembled. Katara took his hands in hers and squeezed them as hard as she could.

"Damn it, Katara! I had her! Why'd you do that?!"

Katara just stared at him, a sad smile on her face. "You know why." she coughed. "Listen… we don't have much time—I don't have much time left…" The breath from her lungs started to falter. "Just know…I love you… And if anyone's going to bring peace to the world, it's you."

Zuko shook his head, clenching his jaw.

"Katara, I—"

His words stop as her hand reached for his scarred cheek. The tears in her eyes were reflective of his own.

"You'll keep your promises right?"

Zuko was shaking from the deep sobs that wracked his body. He couldn't lose her. It just wasn't possible.

"Y-Yes, of course I will."

"I love you." She repeated, desperately.

"I love you too, Katara. Always."

He kissed her lips and forehead as she smiled one last time.

She was gone.

* * *

Murder was a line Zuko didn't cross. However, unlike Aang, he wasn't as naïve to believe that it could never be justified. The world was full of monsters and his sister was one of them.

Sometimes the ends justified the means.

Azula looked gleeful. "Isn't this sweet? Zuzu, you fell for a peasant? How perfectly fitting. A banished prince falling for a savage from a frozen wasteland. I never thought you could shame yourself more. But you always had a knack for proving me wrong."

Zuko wasn't listening. He couldn't.

Noting his silence, she continued. "Awww Zuzu. I didn't _mean_ to strike her, but really, did you honestly expect a future with that witch? She's filthy, just look at her."

Zuko said nothing. No amount of words could voice the anger and resentment he felt. He knew that this was it. He would have to end her.

Zuko threw a bright fist of flames at Azula, causing the princess to draw back a few paces. He stood, letting the electric currents run through his body. He released the lightning, piercing through Azula's shoulder.

The shock on his sisters face wasn't what stopped him. The look of fear was. In all his life, the one thing Azula never was, was afraid.

He couldn't do it. As much as his sister deserved to die, he just couldn't—because even after everything, at the end of the day, she was still his sister.

He briefly wondered if Katara would be disappointed in him.

Without looking at her face. he dragged a barely conscious Azula and used the chains near the palace columns to keep her contained.

As the sages declared Zuko the winner of the duel, he only had one thing on his mind—_rage_.


	2. Fire is Life

_**Chapter 2: Fire is Life**_

"Help me off this thing! I can't see anything!"

"I've got you Toph. We're on solid ground now, so you can let go of me."

Sokka, Toph, and Suki successfully destroyed the airships that we're headed towards the Earth Kingdom. After seeing Aang defeat Ozai, and marveling over how Aang took away his bending, they decided to head towards the Fire Nation, with said Fire Lord, to help Zuko and Katara.

Sokka hoped his sister was okay. He knew she was strong and powerful, but at the end of the day, she was still his baby sister and would chase her all over the world if it meant her safety. As they neared the palace, Aang steered Appa to a stop, placing him by a nearby shed. Toph shoved Sokka out of the way to get off.

"Finally! Sweet, sweet land!"

Suki rolled her eyes. "You've only been in the air for fifteen minutes. Not fifteen days."

Toph blew a stray hair from her face. "Whatever. It beats being near Snoozles and his smelly feet."

Sokka scoffed. "Excuse me?! My feet don't smell! Do they smell Suki?" Suki giggled a bit before helping Sokka off the bison. "Kind of."

Aang patted Appa in reassurance. "We'll have to leave you here for now, but we'll be back soon!" The bison groaned in reply and the Gaang headed to the palace.

* * *

The Sages approached them, bowing their heads. "Avatar Aang, it is an honor to meet you."

Aang bowed in respect. "The honor is mine. Ozai is in the saddle, we couldn't carry him, but he's unconscious—I took his bending away. Please secure him in a cell immediately."

One of the Sages fidgeted a bit, nervously glancing up at the boy. "Yes, Avatar," Two of the Sages take Ozai into the palace to secure him, while one remains. "Avatar, I hate to be the bringer of bad news, but it seems that one of your friends did not survive Azula's wrath."

Aang paused. The rest of the group gasped, but Sokka stepped forward. "Was it my sister? Is Katara…gone?"

A heavy silence draped over the air, like it was suffocating the very atmosphere itself. "We are sorry, but it appears so."

Sokka turned his head, hands clenched. "Can I—Can we see her?" The Sages nodded and guided them into the palace.

* * *

Zuko's room was a mess.

Empty wine bottles were scattered on the ground, scrolls were tossed carelessly into oblivion—even one of his mother's old romance scrolls.

Nothing mattered right now, not even that.

Zuko had no idea how long he had been pacing his room, but he was pretty sure it had been a few hours.

It had been a few hours since Katara died.

_His Katara_, he thought despairingly.

There was a numbing, desolate feeling to the room. He missed her smelly sea prunes, her lean figure, bending the waves of the sea, as if _she_ were their commander. He missed her smile, the kind that made him return the gesture regardless of the situation—the kind that gave hope for the future.

He never imagined one where Katara was not in it.

The Sages told him they were going to send her body off to be cremated at her home in the Southern Water Tribe—a place she dwelled before his interference. Maybe she would've still been alive, had he not shown up.

Or maybe not.

Zuko knew he had to go see her one last time before she was sent away from him forever.

* * *

The Gaang followed the Sages through three corridors that led to the throne room, an empty silence followed. Suki and Aang helped Sokka most of the way due to his injured leg, but Sokka couldn't care less about that.

His sister was gone and there was nothing he could do.

Part of him—the irrational side of him—wanted to blame the prince, for even putting his sister in harm's way. But he's a logical person and any sane and logical person that knew Zuko knew the boy would give his life for Katara.

"Here we are." The Sages gestured for them to enter the cold room. The room was dark red, and adorned with golden emblems that encased the walls. Three fire symbols were painted on the hard floor. There was a single bed in the middle of the room that held Katara.

Sokka was the first to make it to the bed. The tears he suppressed earlier slowly ran down his face as he cried.

"Kat-Katara, I'm so sorry. I…I failed you. I should've been here. You needed me and I wasn't here."

The rest of the Gaang surrounded Katara, silently crying. Aang, who had let go of his irrational attachment to the waterbender long ago, gave her a peck on the cheek and silently recited an old Air Nomad prayer. Sokka looked up to see a red-eyed Zuko in the doorway, looking disheveled.

"She—she risked her life for me. I wasn't fast enough—"

Sokka enveloped Zuko in a brotherly hug as they both cried. A moment passed before Aang spoke up.

"Your father…he's secured in a cell. I…took away his bending."

Zuko's eyes widened, but narrowed almost immediately. He would worry about his father later, right now he needed to grieve in order to move on.

_If I ever move on_, he thought, bitterly.

"Guys…I need a moment. Her body will be sent off soon to be cremated and I just—"

Sokka patted his shoulder knowingly. "It's alright. We'll go. I know how much you loved her."

_Loved_, Zuko thought, numbly. Sokka said that in the present tense, as if he'd ever overcome that feeling.

The rest of the Gaang left him to his own devices and closed the door behind him.

* * *

_Katara placed her hands on her hips. "That's not fair! You cheated!"_

_"What? I simply just threw a flame—"_

_"Zuko, I almost flew from that blast! You're lucky I didn't freeze you to a tree!"_

_Zuko put his hands on his hips to mimic Katara, "Oh boo-hoo, you'll get over it."_

_"Oh yeah? Get over **this**!"_

_Katara rose her arms and bended the water to create a huge a wave and threw it towards Zuko. Zuko tried to evade it, but wasn't successful._

_"Ha! **I'm** the winner and **you're** the loser!" The waterbender placed her slender sienna hands on her hips, "Since you lost, you have to do all our laundry."_

Zuko tried to avoid thinking of the past, but he couldn't help it. It kept replaying over and over again and he wasn't sure he wanted it to stop or keep going.

"Katara, I miss you so much. I know this is…odd, considering you're in front of me, but, Zuko clenched and unclenched his hands, "You're everything to me, you stubborn idiot. I'm going to be crowned Fire Lord soon, and the ironic thing is that for so long, the throne was one of the things I would've died for. Now I don't even care." He let a stray tear roll down his face as he put his forehead near her heart and simply laid there.

Through his morbid thoughts, he couldn't help but notice that there was a small thump. Like the sound of a heartbeat. Curiously, he put his ear on her heart and gasped.

There _was_ a heartbeat. It was faint, but it was still there, thudding like the sound of a soldier's footsteps.

Zuko panicked. He wanted to call for the physician, but something in his core told him that this was something he had to do on his own. He recalled a conversation he had with his uncle.

* * *

_"Nephew, there is something I want to teach you. Something that even Azula and your father do not have knowledge of."_

_Zuko perked up, ready to take in this sacred knowledge. "What is it, Uncle?"_

_Iroh put on a pot of boiling water before adding the crushed herbs and spices into it. "It is a technique called Flame Healing."_

_Zuko's eyes narrowed. His mother had often read him and Azula fairy tales of firebenders that could heal almost any wound, no matter how small or large. No one ever took it seriously though. It was a story that was often told to younger children for amusement._

_"Isn't that just a fairy tale? No firebender can heal—fire just destroys anything and everything."_

_An amused smile played upon Iroh's lips. "It is often the most concealed of things that tend to be the most powerful."_

_Zuko groaned. He really didn't have time for his uncle's stupid proverbs. "Would you just tell me already?"_

_"Fair enough," He set down his tea and gave Zuko a solemn look, "Zuko, this technique is very useful, but there are serious consequences of using it. Flame healing requires an extreme amount of chi—some have lost their bending entirely because of it, and some have even died."_

_"Then why are you telling me this?! How do you even know about this?"_

_"Iroh sighed. "Just because something is dangerous does not mean it cannot be useful. If used correctly, you should be fine. I have a few older friends that know the sacred ways of the old Fire Nation—the nation that was once known to subscribe to the ideas__ of pride, peace, and prosperity."_

_Zuko had an idea of who these 'friends' were. He remembered his uncle playing Pai Sho with some older men, as if they had no care in the world._

_Iroh kneeled and closed his eyes, gesturing Zuko to do the same._

* * *

Zuko closed his eyes and concentrated on the flow of energy within him.

Zuko closed his eyes and inhaled, letting the flow of his chi circulate throughout his body. He opened his eyes and lightly placed his pale hands on Katara's heart.

_Agni, please let this work._

Nothing happened.

Zuko continued to let his chi flow, guiding it towards his hands. The immense heat pressure in his fingers left his body and covered his hand in a soft gold glow, causing the whole room to radiate with his power.

Closing his eyes, he began to guide the warmth to Katara's heart, coating the organ with his chi. As he continued, he noticed her body temperature was beginning to gradually increase, and her lips were regaining their dark pink tint. Her sallow skin began to regain its normal sienna shade. This encouraged him to keep going, despite the black dots filling his vision.

Unbeknownst to Zuko, Sokka snuck back in to give one last goodbye to his sister, only to stumble upon Zuko doing something.

He didn't try to interrupt him. Sokka had a feeling that whatever he was doing was going to help his sister.

Katara's eyes finally opened and as she sat up with a gasp, Zuko, having spent all his energy on restoring her body, collapsed on the floor.

Katara, too weak to tend to Zuko, struggled to leave the bed. Sokka ran to his side instead.

"Zuko!"

* * *

Katara woke up in a daze, wondering where she was until she saw Zuko lying on a small couch on the other side of the room. He was covered by a long, burgundy blanket—resting peacefully.

All she remembered was that he did something to her, to…revive her, but she wasn't sure what.

She was _so_ sure she was dead.

Before she had passed out again, Sokka quickly told her what had happened. Apparently, he came in to say one last goodbye, that is, until he caught Zuko standing by Katara, his hands on her chest glowing a bright gold. He didn't protest because his instincts told him that whatever he was doing was going to help her.

_And Sokka's instincts are always right,_ he said proudly.

Katara could hardly believe that Zuko had healing powers. She had never heard of any element, aside from water, that had the ability to heal.

_"Fire is life. Sure, it can destroy, but every element has a flip side to it."_

_Katara pondered for a moment. "So, when we make campfires, the fire provides us with warmth, therefore, shielding us from the cold that could ultimately kill us."_

_Zuko's eyes glimmered in the firelight. "Exactly."_

So was this one of fire's greatest abilities? To also _heal_? The idea of Zuko being a healer such as herself made her giddy. She'd never known a healer from another element, let alone a _male _healer. Her memories from her visit of the Northern Water Tribe still left a bitter taste in her mouth. Men were only allowed to fight and the women were to heal. Meeting a male healer of her opposite element was an entirely new experience.

With this knowledge, she slowly crept to where Zuko was resting. She moved his wild, raven hair and just watched how peaceful he looked.

"You know, if you keep staring at me, your eyes might fall out."

Katara shrieked and backed away from him. "Damn it, Zuko! You scared me!"

He let out a snort. "We both nearly died from fighting Azula, but somehow _that_ scared you. You're unbelievable."

Katara crossed her arms. "Whatever. Did—how did you do it? How'd you heal me?"

Zuko pinched the bridge of his nose as he rose up, the blanket falling off his elegant robes. "Uh, it's a firebending technique Uncle taught me. It's called Flame Healing—and it's extremely dangerous. I thought it was just a myth or a fairytale, but it's real." He put his hands over his face. "I had to do something. I heard your heartbeat—it was faint, but it was there. I didn't just make a promise to you, I made a promise to myself—to protect you at any cost."

Katara's eyebrows creased in concern before flinging herself onto Zuko. With a yelp, they both fell on the couch, Katara still holding him. "Thank you. Thank you so much."

"You're welcome. But you should know…I'm angry with you."

Katara broke away and rose an eyebrow. "Oh? And why is that?"

"You _know_ why."

"Zuko—"

"Katara, I watched you die!" Katara flinched.

"I had her!_ I had Azula!_ You know I can redirect lightning and yet—"

"—and yet I did it anyway." Katara finished. "Look, I had to watch my _mother_ die. I watched her sacrifice herself for _me_. I wasn't about to let someone I love do the same."

Zuko closed his mouth. He wasn't sure how to respond to that.

"It was my choice and if I had to do it all over again, I'd do it without hesitation."

Zuko gave a long sigh. "I know, and I'm not sure if I should be happy about that or not."

Katara held the scarred side of his face, letting Zuko lean into it. "I know."

* * *

The coronation ceremony was about to start and Katara was still struggling with her dress. Although she was healed, her body was still sore and aching.

"Ugh, damn it! Why did Ty Lee give me the _tightest_ dress ever? I'm going to freeze her—"

"Need some help with that?"

"Zuko! Oh, thank Tui and La, you're here. Help me please!"

He had to bite back a smile to prevent Katara from fussing even more than she already was. "Oh, calm down. I've got it."

Katara huffed as Zuko gently pulled her arm through the long sleeve and placed her arm back by her side.

"I could've done that if I wasn't still so sore, you know."

He pulled her in by her waist and placed a kiss on her nose. "Yeah, yeah."

"So, how do you feel? You know, about being the next Fire Lord and all?"

A moment passed before Zuko spoke up. "There's so much I have to do. It'll take years before everything is truly peaceful again."

"So much _you_ have to do? Don't you mean 'we'?" Katara scoffed. "After I help rebuild my home, I'm coming back here. I hope you're willing to have me."

"I haven't forgotten about that promise, you know."

Katara smirked. "I know."

Zuko couldn't help the grin that crept on his face. "Are you asking to be my Fire Lady?"

Katara playfully punched him and he laughed. "The Southern Water Tribe will always be in my heart. I've realized now that destiny is what _you_ make of it, not what everyone wants it to be."

Zuko remained silent as she continued.

"I've realized that my destiny is helping to restore balance in the world. And while helping Aang was a huge part of it, there's still so much more that I want to do. So, yes—I do intend on being Fire Lady in the near future. I want to help here in the Fire Nation in any way I can, as well as helping the Water Tribes and the Earth Kingdom reconstruct. It won't be easy, but when have we ever been easy?"

The feeling of Zuko's lips on hers sent her into overdrive, as she kissed him back. "I've always wanted to hear you say that."

"Oh? Say what?"

Zuko gave her a loving smile. "Say that you'll be mine."


End file.
